Percussion devices, such as handheld or hand-maneuvered drilling machines, often contain a recoil damper to absorb the cyclic recoil from the drill string/shank adaptor and to prevent it from continuing to be displaced inside the machine housing that contains the percussion device's percussion mechanism. This results in lower vibration levels and less noise, which results in an improved and healthier work environment for operators, and less disruption for people in the surrounding area. This also means that it is simpler for operators to handle the percussion device. The continuous mechanical forces that arise during the use of the percussion device can namely require significant strength of an operator to handle the percussion device.
U.S. Pat. No. 5,996,708 discloses a percussion device that comprises an axially displaceable shank adaptor that is arranged to hold a tool and a percussion piston that is arranged to carry out a reciprocating movement caused by the pressure from a hydraulic fluid and to strike the shank adaptor when the percussion device is in use. The percussion device comprises a recoil damper to dampen the recoil from the shank adaptor. The recoil damper consists of a hollow transmission element that contains an elastic ring and a stop ring. The elastic ring and stop ring are clamped in the transmission element of a locking element. The shank adaptor is arranged to strike a bevel on the stop ring during its recoil. In order to assemble the recoil damper the stop ring and the elastic ring must be placed in the hollow transmission element and be fixedly locked using the locking element. The recoil damper can thereafter be mounted inside the percussion device as a unit.